Ambient occlusion broken on multiple levels

Problem 1: Try enabling ambient occlusion. Changing to a > 0 value has no visible effect. This must be some minor glitch somewhere since in our port in the new Qt3D-based runtime this is not an issue.

Update: I realize now that playing with aobias ("AO Threshold") we can get better looking results. So maybe problem 2 is not a problem after all.

Problem 2: Under the hood this does enable the SSAO texture generation, though. However, the intermediate texture looks like the attached picture. (ssaotexture_weird.png) This cannot be right.

With the new Qt3D-based runtime enabling ao does show up in the final result, but - due to the same weird intermediate SSAO texture - it only adds some ugly "banding" (the stripes) to the end result and is nothing like a proper AO implementation.

HBAO in NDD works fine and darkens only where expected, see second attached screenshot showing a "proper" SSAO texture at aostrength=100. (ssaotexture_great.png)

It could be a misunderstanding too (obviously the simple SSAO we have now cannot be as good as HBAO+) so if that's the case please confirm what parameters are needed to get a decent looking AO.